US4002731A - Diagnostic process using sodium tyropanoate - Google Patents
Diagnostic process using sodium tyropanoate Download PDFInfo
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- US4002731A US4002731A US05/479,634 US47963474A US4002731A US 4002731 A US4002731 A US 4002731A US 47963474 A US47963474 A US 47963474A US 4002731 A US4002731 A US 4002731A
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- gallbladder
- sodium
- tyropanoate
- sodium tyropanoate
- iodine
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K49/00—Preparations for testing in vivo
- A61K49/04—X-ray contrast preparations
- A61K49/0433—X-ray contrast preparations containing an organic halogenated X-ray contrast-enhancing agent
- A61K49/0447—Physical forms of mixtures of two different X-ray contrast-enhancing agents, containing at least one X-ray contrast-enhancing agent which is a halogenated organic compound
- A61K49/0495—Physical forms of mixtures of two different X-ray contrast-enhancing agents, containing at least one X-ray contrast-enhancing agent which is a halogenated organic compound intended for oral administration
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K9/00—Medicinal preparations characterised by special physical form
- A61K9/48—Preparations in capsules, e.g. of gelatin, of chocolate
- A61K9/50—Microcapsules having a gas, liquid or semi-solid filling; Solid microparticles or pellets surrounded by a distinct coating layer, e.g. coated microspheres, coated drug crystals
- A61K9/5005—Wall or coating material
- A61K9/5015—Organic compounds, e.g. fats, sugars
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K9/00—Medicinal preparations characterised by special physical form
- A61K9/48—Preparations in capsules, e.g. of gelatin, of chocolate
- A61K9/50—Microcapsules having a gas, liquid or semi-solid filling; Solid microparticles or pellets surrounded by a distinct coating layer, e.g. coated microspheres, coated drug crystals
- A61K9/5005—Wall or coating material
- A61K9/5021—Organic macromolecular compounds
- A61K9/5036—Polysaccharides, e.g. gums, alginate; Cyclodextrin
- A61K9/5042—Cellulose; Cellulose derivatives, e.g. phthalate or acetate succinate esters of hydroxypropyl methylcellulose
- A61K9/5047—Cellulose ethers containing no ester groups, e.g. hydroxypropyl methylcellulose
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K9/00—Medicinal preparations characterised by special physical form
- A61K9/48—Preparations in capsules, e.g. of gelatin, of chocolate
- A61K9/50—Microcapsules having a gas, liquid or semi-solid filling; Solid microparticles or pellets surrounded by a distinct coating layer, e.g. coated microspheres, coated drug crystals
- A61K9/5084—Mixtures of one or more drugs in different galenical forms, at least one of which being granules, microcapsules or (coated) microparticles according to A61K9/16 or A61K9/50, e.g. for obtaining a specific release pattern or for combining different drugs
Definitions
- This invention relates to a new diagnostic process and new formulation used therein, and in particular is concerned with a new procedure for oral cholecystography and a sustained release formulation employed therein.
- Sodium tyropanoate sodium beta-(3-butyramido-2,4,6-triiodophenyl)-alpha-ethylpropionate is the most recent addition to the armamentarium of oral cholecystographic agents (U.S. Pat. No. 2,895,988).
- iopanoic acid [beta-(3-amino-2,4,6-triiodophenyl)-alpha-ethylpropionic acid]
- ipodate [beta-(3-dimethylaminomethyleneamino-2,4,6-triiodophenyl)propionic acid] and its sodium and calcium salts.
- the conventional cholecystographic procedure comprises oral administration of a single dose of contrast agent (25-100 milligrams per kilogram of body weight) sufficient to produce adequate visualization of the gallbladder at the time of maximum concentration of iodine in the gallbladder (about 10-16 hours after administration). Shortly after administration of the contrast agent there is an initial surge in blood iodine levels to a relatively high concentration, followed by a gradual decrease.
- contrast agent 25-100 milligrams per kilogram of body weight
- the process of the invention thus comprises administering orally to a mammalian organism possessing a gallbladder, continuously or intermittently over a period of between about 4 and about 10 hours, a diagnostically effective amount of sodium tyropanoate, whereby a concentration of iodine in the gallbladder sufficient to provide adequate visualization of the gallbladder is obtained, while maintaining the maximum iodine concentration in the blood significantly lower than the maximum iodine concentration in the blood obtained by oral administration of an initial single dose of the same total amount of sodium tyropanoate.
- the sodium tyropanoate can be administered in several divided doses (intermittent administration) or in a sustained or controlled release formulation (continuous administration).
- the total dose of sodium tyropanoate is preferably between 25 and 100 milligrams per kilogram of body weight.
- the sodium tyropanoate is preferably administered in from three to six approximately equally divided doses at approximately equal intervals over a period of between 4 and 10 hours.
- maximum gallbladder contrast medium density is obtained about fourteen hours after the initial administration; and maximum iodine blood levels occur after about 6 or 7 hours, said maximum being only about 65% that of the maximum iodine blood levels obtained about 2 hours after administration of a single undivided dose.
- the sodium tyropanoate When the sodium tyropanoate is administered in sustained release form it is given as a single undivided dose containing sufficient contrast agent to provide adequate X-ray visualization of the gallbladder.
- the contrast medium is continuously gradually released in the gastrointestinal tract over a period of up to about 10 hours, and the iodine blood levels are at all times significantly below those obtained after administration of a single undivided dose of sodium tyropanoate not formulated for sustained release.
- Sustained or controlled release formulations are known in the art (Remington's Pharmaceutical Sciences, 14th Edition, Chapter 89, pp. 1702-1711). They comprise a mixture or coating of the active ingredient with an additive or additives which slow down the release and absorption of the drug or diagnostic agent in the gastrointestinal tract so as to extend the action of the active ingredient over a desired length of time.
- Appropriate additives for the sustained release preparations are high molecular weight and polymeric substances. These include various cellulose derivatives, e.g. ethylcellulose, methylcellulose, carboxymethylcellulose, hydroxypropylcellulose and the like; higher molecular weight acids, esters and salts thereof, e.g. alginic acid, metal salts of higher fatty acids, glyceryl esters of higher fatty acids, carnauba wax, beeswax, spermaceti, hydrogenated castor oil, and the like; and synthetic polymers, e.g. polyvinylpyrrolidine, polyvinyl alcohol, polyethylene glycol, carboxyvinyl polymer and the like.
- cellulose derivatives e.g. ethylcellulose, methylcellulose, carboxymethylcellulose, hydroxypropylcellulose and the like
- higher molecular weight acids, esters and salts thereof e.g. alginic acid, metal salts of higher fatty acids, glyce
- the sustained release preparations are prepared by coating granules, beads or pellets of the active ingredient with one or more additives such as those named above.
- a preferred type of sustained release preparation of the present invention comprises a granulation of sodium tyropanoate coated with a cellulose derivative.
- Other additives such as hydrogenated castor oil may be present.
- the weight of total additives, not including other excipients and binders such as talcum, lactose, starch, Avicel (microcrystalline cellulose), is about 5% of the weight of the sodium tyropanoate.
- sustained release preparation of sodium tyropanoate is conveniently prepared for use in unit dosage form, in tablets or capsules, each unit comprising about 250 and 1000 milligrams of sodium tyropanoate. If desired the sustained release form can be mixed with up to about one-third uncoated sodium tyropanoate in the event a greater initial absorption of the contrast medium is desired while retaining the advantages of the sustained release.
- Regimen A is the conventional mode of administration except for the placebo doses.
- Regimens B and C are true divided doses.
- the drugs were double-blinded and all possible variables, e.g. equipment, diet, etc. were well controlled insofar as possible.
- X-ray visualization of the gallbladder was performed at 4, 7, 14 and 24 hours after the first capsules were taken. Each film was read blind, independently, by three different radiologists and the Average Cholecystographic Index (ACI) recorded.
- the ACI is a numerical scoring plan measuring the density of the gallbladder shadows based on the following criteria: 0 (none), 1 (poor), 2 (fair), 3 (good), 4 (excellent); cf. Hoppe et al., Am. J. Roentgen. Rad. Therap. Nuc. Med. 69, 620-7 (1953).
- the ACI values for the nine subjects were as follows:
- the four different dosage regimens were given in a blind crossover fashion at 2 week intervals.
- the order of administration was as follows:
- Blood samples for organic bound iodine determinations were obtained from each subject at 0, 2, 4, 6, 7, 9, 11, 14, 18, 24 and 48 hours after drug ingestion from time zero of dosage schedule.
- Urinary pH, volume and iodine concentration levels were determined at 24, 48 and 72 hours from time zero of dosage on each subject.
- Radiographs were obtained at 4, 7, 11 and 14 hours from time zero of each regimen on all subjects.
- the peak blood iodine level for the 3-gram divided dose (Regimen B), 88.18 ⁇ g/ml at 6 hours, is substantially lower (30%) than the peak blood iodine level with the single 3-gram dose (Regimen A), 127.93 ⁇ g/ml at 2 hours. Both regimens produced equivalent good to excellent visualization at 14 hours. Comparing Regimen C (2-gram single dose) and Regimen D (2-gram divided dose), the peak blood iodine level in Regimen D is 32% less than in Regimen C with essentially adequate visualization at 11 and 14 hours on a comparative basis.
- Sustained release preparations of sodium tyropanoate can be prepared by conventional procedures, illustrated as follows:
- Hydrogenated castor oil (Castorwax MP 70) (466.9 grams) and ethylcellulose (233.1 grams) were dissolved in an equal volume mixture of methylene dichloride and acetone to a total volume of 7000 milliliters with gentle heating and agitation. This solution was spray-dried upon the sodium tyropanoate-Avicel pellets until the weight of coating was 5% that of the weight of sodium tyropanoate and at the same time dusted with talcum so that the amount of talcum was 2.4% that of the sodium tyropanoate.
- the resulting coated granulation of sodium tyropanoate was mixed with 8.6% by weight (based on the sodium tyropanoate) of a pelletized excipient granulation prepared from 3 parts by weight of lactose and 1 part by weight each of starch and Avicel, and the final mixture was encapsulated in hard gelatin capsules at 635 milligrams total weight per capsule, each capsule thus containing 500 milligrams of sodium tyropanoate which was confirmed by analysis.
- Each capsule thus had the following composition:
- mice of the foregoing formulation were determined, and a 7-day LD 50 value of 5042 (3623-6596) mg/kg in terms of sodium tyropanoate was obtained. This compared to a LD 50 value of 3158 (1302-3900) for commercial sodium tyropanoate capsule mix (uncoated).
- the sustained release preparation was thus statistically significantly less toxic than the immediate-release material.
- a further formulation was prepared containing 375 milligrams of sustained-release sodium tyropanoate and 125 milligrams of immediate-release sodium tyropanoate, with the following composition:
- sustained-release formulations were tested in male and female cats weighing 2.5 to 3.5 kg by oral administration at a dose level of 100 mg/kg as sodium tyropanoate, and the gall-bladder visualization Cholecystographic Index (CI) and blood iodine levels ( ⁇ g/ml) were determined at selected time intervals by standard methods.
- Parallel studies were carried out on immediate-release (uncoated) sodium tyropanoate preparations. The results are given in the following table:
- Sodium tyropanoate in a divided dose regimen was compared with the chemically related iopanoic acid and its sodium salt in a divided dose regimen as follows: Sodium tyropanoate, iopanoic acid and sodium iopanoate were administered orally at 100 mg/kg to groups of 30 cats. The three compounds were also administered to groups of five cats in divided doses of 20 mg/kg, five times, at 2-hour intervals. X-rays were taken at one-half, 1, 2, 4, 7 and 24 hours post-medication and the gallbladder shadows were assayed by Cholecystographic Index (CI). Blood samples were collected at the same time intervals and the organic bound iodine determined. The results are given in the following table:
Abstract
Divided doses or sustained release formulations of sodium tyropanoate upon oral administration provide adequate gallbladder visualization with substantially lower blood levels than are obtained with conventional single dose administration.
Description
This invention relates to a new diagnostic process and new formulation used therein, and in particular is concerned with a new procedure for oral cholecystography and a sustained release formulation employed therein.
Sodium tyropanoate [sodium beta-(3-butyramido-2,4,6-triiodophenyl)-alpha-ethylpropionate] is the most recent addition to the armamentarium of oral cholecystographic agents (U.S. Pat. No. 2,895,988). Other oral cholecystographic agents still commercially available are iopanoic acid [beta-(3-amino-2,4,6-triiodophenyl)-alpha-ethylpropionic acid], and ipodate [beta-(3-dimethylaminomethyleneamino-2,4,6-triiodophenyl)propionic acid] and its sodium and calcium salts.
Although the foregoing oral cholecystographic agents are relatively non-toxic substances, adverse reactions such as minor gastrointestinal disturbances or allergic reactions are occasionally observed. Therefore, it is highly desirable, in order to minimize the occurrence of these undesirable side-effects, to use as low a dose as possible and maintain the blood plasma iodine concentration at the lowest possible level without sacrificing adequate visualization of the gallbladder.
The conventional cholecystographic procedure comprises oral administration of a single dose of contrast agent (25-100 milligrams per kilogram of body weight) sufficient to produce adequate visualization of the gallbladder at the time of maximum concentration of iodine in the gallbladder (about 10-16 hours after administration). Shortly after administration of the contrast agent there is an initial surge in blood iodine levels to a relatively high concentration, followed by a gradual decrease.
It has now been found that in cholecystographic procedures using sodium tyropanoate, if the latter is administered not in a single dose but in the same quantity distributed over a period of time ranging from about 4 to about 10 hours, there is a significant decrease in the maximum blood iodine levels observed with no appreciable decrease in the maximum contrast medium density obtained in the gallbladder X-ray photographs, as compared with the conventional single dose regimen. This phenomenon is not observed with the other cholecystographic agents, iopanoic acid and ipodate.
The process of the invention thus comprises administering orally to a mammalian organism possessing a gallbladder, continuously or intermittently over a period of between about 4 and about 10 hours, a diagnostically effective amount of sodium tyropanoate, whereby a concentration of iodine in the gallbladder sufficient to provide adequate visualization of the gallbladder is obtained, while maintaining the maximum iodine concentration in the blood significantly lower than the maximum iodine concentration in the blood obtained by oral administration of an initial single dose of the same total amount of sodium tyropanoate.
The sodium tyropanoate can be administered in several divided doses (intermittent administration) or in a sustained or controlled release formulation (continuous administration). The total dose of sodium tyropanoate is preferably between 25 and 100 milligrams per kilogram of body weight.
In the divided dose regimen the sodium tyropanoate is preferably administered in from three to six approximately equally divided doses at approximately equal intervals over a period of between 4 and 10 hours. In man maximum gallbladder contrast medium density is obtained about fourteen hours after the initial administration; and maximum iodine blood levels occur after about 6 or 7 hours, said maximum being only about 65% that of the maximum iodine blood levels obtained about 2 hours after administration of a single undivided dose.
When the sodium tyropanoate is administered in sustained release form it is given as a single undivided dose containing sufficient contrast agent to provide adequate X-ray visualization of the gallbladder. The contrast medium is continuously gradually released in the gastrointestinal tract over a period of up to about 10 hours, and the iodine blood levels are at all times significantly below those obtained after administration of a single undivided dose of sodium tyropanoate not formulated for sustained release.
Sustained or controlled release formulations are known in the art (Remington's Pharmaceutical Sciences, 14th Edition, Chapter 89, pp. 1702-1711). They comprise a mixture or coating of the active ingredient with an additive or additives which slow down the release and absorption of the drug or diagnostic agent in the gastrointestinal tract so as to extend the action of the active ingredient over a desired length of time.
Appropriate additives for the sustained release preparations are high molecular weight and polymeric substances. These include various cellulose derivatives, e.g. ethylcellulose, methylcellulose, carboxymethylcellulose, hydroxypropylcellulose and the like; higher molecular weight acids, esters and salts thereof, e.g. alginic acid, metal salts of higher fatty acids, glyceryl esters of higher fatty acids, carnauba wax, beeswax, spermaceti, hydrogenated castor oil, and the like; and synthetic polymers, e.g. polyvinylpyrrolidine, polyvinyl alcohol, polyethylene glycol, carboxyvinyl polymer and the like.
The sustained release preparations are prepared by coating granules, beads or pellets of the active ingredient with one or more additives such as those named above. A preferred type of sustained release preparation of the present invention comprises a granulation of sodium tyropanoate coated with a cellulose derivative. Other additives such as hydrogenated castor oil may be present. The weight of total additives, not including other excipients and binders such as talcum, lactose, starch, Avicel (microcrystalline cellulose), is about 5% of the weight of the sodium tyropanoate.
The sustained release preparation of sodium tyropanoate is conveniently prepared for use in unit dosage form, in tablets or capsules, each unit comprising about 250 and 1000 milligrams of sodium tyropanoate. If desired the sustained release form can be mixed with up to about one-third uncoated sodium tyropanoate in the event a greater initial absorption of the contrast medium is desired while retaining the advantages of the sustained release.
In addition to the advantage of the sustained release preparation in producing lower blood iodine levels, it has also been found that the acute oral toxicity in mice of the sustained release preparation of sodium tyropanoate was significantly less than that of commercial, uncoated sodium tyropanoate.
The following clinical and laboratory data will further illustrate the invention without the latter being limited thereby.
A divided dose study with sodium tyropanoate (commercial BILOPAQUE, uncoated) was carried out in nine humans, all healthy males and females between 20 and 30 years of age. Each individual received the following three regimens, one regimen given each week in random order for a 3-week period:
______________________________________
Hours
0 2 4 6
______________________________________
Regimen A:
3 grams Placebo Placebo Placebo
Regimen B:
750 mg 750 mg 750 mg 750 mg
Regimen C:
375 mg 375 mg 375 mg 375 mg
______________________________________
Regimen A is the conventional mode of administration except for the placebo doses. Regimens B and C are true divided doses. The drugs were double-blinded and all possible variables, e.g. equipment, diet, etc. were well controlled insofar as possible. X-ray visualization of the gallbladder was performed at 4, 7, 14 and 24 hours after the first capsules were taken. Each film was read blind, independently, by three different radiologists and the Average Cholecystographic Index (ACI) recorded. The ACI is a numerical scoring plan measuring the density of the gallbladder shadows based on the following criteria: 0 (none), 1 (poor), 2 (fair), 3 (good), 4 (excellent); cf. Hoppe et al., Am. J. Roentgen. Rad. Therap. Nuc. Med. 69, 620-7 (1953). The ACI values for the nine subjects were as follows:
______________________________________ Dose Hours Postmedication Regimen 4 7 14 24 ______________________________________ A 1.4 2.4 3.5 0 B 1.0 2.3 3.5 0 C 0.0 1.0 2.4 0 ______________________________________
The ACI values for Regimen A (single 3 gram dose) and Regimen B (3 gram divided dose) were almost identical indicating that the divided dose could provide adequate visualization.
The average plasma iodine concentrations in micrograms per milliliter in the nine subjects are given in the following table:
______________________________________ Dose Hours Postmedication Regimen 1/2 1 2 4 7 24 ______________________________________ A 10.8 77.3 125.0 104.5 55.2 18.9 B 9.7 25.2 24.5 57.5 81.8 16.8 C 2.9 9.5 9.9 19.8 45.8 7.5 ______________________________________
The data show that the maximum plasma iodine level with Regimen B (divided 3 gram dose), 81.8 μg/ml at 7 hours, was substantially lower than the maximum level with Regimen A (single 3 gram dose), 125.0 μg/ml at 2 hours. This lowering of plasma iodine levels was consistent in all nine subjects. The lowering of serum uric acid with Regimen A and B was almost identical.
In a second study, four different dosage regimens of sodium tyropanoate (commercial BILOPAQUE, uncoated) were evaluated in four healthy subjects, as follows:
__________________________________________________________________________
Hours
0 1 2 3 4 5
__________________________________________________________________________
Regimen A:
3 gram
Placebo
Placebo
Placebo
Placebo
Placebo
Regimen B:
500 mg
500 mg
500 mg
500 mg
500 mg
500 mg
Regimen C:
2 gram
Placebo
Placebo
Placebo
Placebo
Placebo
Regimen D:
333 mg
333 mg
333 mg
333 mg
333 mg
333 mg
__________________________________________________________________________
The four different dosage regimens were given in a blind crossover fashion at 2 week intervals. The order of administration was as follows:
______________________________________
Regimen
Volunteer
Week 1 Week 3 Week 5 Week 7
______________________________________
1 A B C D
2 B C D A
3 C D A B
4 D A B C
______________________________________
Blood samples for organic bound iodine determinations were obtained from each subject at 0, 2, 4, 6, 7, 9, 11, 14, 18, 24 and 48 hours after drug ingestion from time zero of dosage schedule.
Urinary pH, volume and iodine concentration levels were determined at 24, 48 and 72 hours from time zero of dosage on each subject.
Radiographs were obtained at 4, 7, 11 and 14 hours from time zero of each regimen on all subjects.
The results for each medication regimen for blood iodine levels, total urinary iodine excretion over a 72-hour period postmedication, and radiological appraisal of gall-bladder visualization at 4, 7, 11 and 14 hours postmedication are presented as averages for the four subjects in the following table:
__________________________________________________________________________
Regimen
Results at
A B C D
Hours Post-
(3 gram -
(3 gram -
(2 gram -
(2 gram -
Medication
single dose)
divided dose)
single dose)
divided dose)
__________________________________________________________________________
BLOOD IODINE - μg/ml
0 0.18 0.20 0.20 0.35
2 127.93 54.08 86.30 24.38
4 87.40 58.60 61.25 58.48
6 56.70 88.18 31.98 57.15
7 52.35 87.85 25.03 47.53
9 34.23 57.73 21.35 29.60
11 26.78 44.30 20.10 23.88
14 23.60 31.10 17.55 19.50
18 23.83 26.25 16.90 15.05
24 19.08 20.15 14.25 10.78
48 11.08 9.52 5.35 6.40
URINE IODINE - mg/d
24 373.28 459.63 336.10 170.00
48 175.55 188.83 146.33 127.60
72 100.00 78.70 60.85 84.10
648.83 727.16 543.28 381.70
X-RAY ACI (0-4)
4 2.8 1.0 2.2 .5
7 3.2 2.4 2.5 1.0
11 3.7 2.9 2.3 2.2
14 3.6 3.7 2.6 2.1
__________________________________________________________________________
The peak blood iodine level for the 3-gram divided dose (Regimen B), 88.18 μg/ml at 6 hours, is substantially lower (30%) than the peak blood iodine level with the single 3-gram dose (Regimen A), 127.93 μg/ml at 2 hours. Both regimens produced equivalent good to excellent visualization at 14 hours. Comparing Regimen C (2-gram single dose) and Regimen D (2-gram divided dose), the peak blood iodine level in Regimen D is 32% less than in Regimen C with essentially adequate visualization at 11 and 14 hours on a comparative basis.
Sustained release preparations of sodium tyropanoate can be prepared by conventional procedures, illustrated as follows:
Sodium tyropanoate (11,250 grams) and 1,238 grams of Avicel were wet granulated with de-ionized water, then extruded and pelletized and dried at 50° C. The dried pellets were classified with No. 16 and No. 30 mesh screens. The pellets passing the No. 16 screen but retained on the No. 30 screen were retained for coating.
Hydrogenated castor oil (Castorwax MP 70) (466.9 grams) and ethylcellulose (233.1 grams) were dissolved in an equal volume mixture of methylene dichloride and acetone to a total volume of 7000 milliliters with gentle heating and agitation. This solution was spray-dried upon the sodium tyropanoate-Avicel pellets until the weight of coating was 5% that of the weight of sodium tyropanoate and at the same time dusted with talcum so that the amount of talcum was 2.4% that of the sodium tyropanoate.
The resulting coated granulation of sodium tyropanoate was mixed with 8.6% by weight (based on the sodium tyropanoate) of a pelletized excipient granulation prepared from 3 parts by weight of lactose and 1 part by weight each of starch and Avicel, and the final mixture was encapsulated in hard gelatin capsules at 635 milligrams total weight per capsule, each capsule thus containing 500 milligrams of sodium tyropanoate which was confirmed by analysis. Each capsule thus had the following composition:
______________________________________
Formulation I
______________________________________
Sodium tyropanoate 500.0 mg
Microcrystalline cellulose (Avicel)
63.6
Hydrogenated castor oil 16.7
Ethylcellulose 8.3
Talcum 12.0
Lactose 25.8
Starch 8.6
635.0 mg
______________________________________
The acute oral toxicity in mice of the foregoing formulation was determined, and a 7-day LD50 value of 5042 (3623-6596) mg/kg in terms of sodium tyropanoate was obtained. This compared to a LD50 value of 3158 (1302-3900) for commercial sodium tyropanoate capsule mix (uncoated). The sustained release preparation was thus statistically significantly less toxic than the immediate-release material.
Similar sustained-release preparations were prepared wherein the ethylcellulose was replaced by methylcellulose.
A further formulation was prepared containing 375 milligrams of sustained-release sodium tyropanoate and 125 milligrams of immediate-release sodium tyropanoate, with the following composition:
______________________________________
Formulation II
______________________________________
Controlled-release pellets
Sodium tyropanoate 375.0 mg
Microcrystalline cellulose (Avicel)
41.3
Hydrogenated castor oil 12.5
Ethylcellulose 6.2
Talcum 9.0
Immediate-release pellets
Sodium tyropanoate 125.0 mg
Microcrystalline cellulose (Avicel)
13.75
Excipient pellets
Lactose 31.35 mg
Starch 10.45
Microcrystalline cellulose (Avicel)
10.45
635.0 mg
______________________________________
The sustained-release formulations were tested in male and female cats weighing 2.5 to 3.5 kg by oral administration at a dose level of 100 mg/kg as sodium tyropanoate, and the gall-bladder visualization Cholecystographic Index (CI) and blood iodine levels (μg/ml) were determined at selected time intervals by standard methods. Parallel studies were carried out on immediate-release (uncoated) sodium tyropanoate preparations. The results are given in the following table:
__________________________________________________________________________
TIME
Dose mg/kg Number
0 1/2 Hour
Group
Formulation
as Na Tyropanoate
of Cats
CI
I.sub.2
CI
I.sub.2
__________________________________________________________________________
I. Na Tyropanoate
100 6 0 0 0 .102
80 mesh powder
(control)
II. Na Tyropanoate
100 5 0 0 0 .101
granulated
uncoated
III.
Formulation I
100 6 0 0 0 .021
Controlled
Release (all
drug coated)
IV. Na Tyropanoate
80 mesh powder
(uncoated)
33
plus plus 9 0 0 0 .034
Na Tyropanoate
67
(coated)
__________________________________________________________________________
TIME (Hours)
1 2 4 7 24
Group
CI I.sub.2
CI I.sub.2
CI I.sub.2
CI I.sub.2
CI I.sub.2
__________________________________________________________________________
I. 0.2
.167
1.6
.154
3.1
.069
4.0
.025
4.0
.006
II. 0.6
.137
1.4
.153
2.6
.092
3.8
.033
4.0
.007
III.
0.5
.060
0.8
.061
1.8
.024
2.8
.023
3.3
.007
IV. 0.4
.058
1.4
.092
3.1
.033
4.0
.018
4.0
.006
__________________________________________________________________________
The results showed that the uncoated sodium tyropanoate formulations (Groups I and II) and the sustained release formulations (Groups III and IV) all gave good to excellent visualization after seven hours, and that iodine blood levels with the sustained release formulations (Groups III and IV) were markedly lower at all times than with the uncoated formulations (Groups I and II). After 24 hours the blood iodine had essentially disappeared for all groups.
Sodium tyropanoate in a divided dose regimen was compared with the chemically related iopanoic acid and its sodium salt in a divided dose regimen as follows: Sodium tyropanoate, iopanoic acid and sodium iopanoate were administered orally at 100 mg/kg to groups of 30 cats. The three compounds were also administered to groups of five cats in divided doses of 20 mg/kg, five times, at 2-hour intervals. X-rays were taken at one-half, 1, 2, 4, 7 and 24 hours post-medication and the gallbladder shadows were assayed by Cholecystographic Index (CI). Blood samples were collected at the same time intervals and the organic bound iodine determined. The results are given in the following table:
______________________________________
Average Cholecysto-
Dose No. graphic Index (CI)
in of Hours Post-Medication
Compound mg/kg Cats 0 1/2 1 2 4 7 24
______________________________________
Sodium 100 30 0 0 0.5 1.6 3.1 3.7 3.9
tyropanoate
20/2Hr. × 5
5 0 0 0.4 1.8 3.0 3.6 4.0
Iopanoic 100 30 0 0 0 0 0.2 1.2 3.6
acid 20/2Hr. × 5
5 0 0 0 0 0 0.8 2.8
Sodium 100 30 0 0 0 0 0.6 1.7 3.7
iopanoate
20/2Hr. × 5
5 0 0 0 0 0 0.8 3.6
______________________________________
Dose Microgm. Compound/ml Plasma
in Hours Post-Medication
Compound
mg/kg 0 1/2 1 2 4 7 24
______________________________________
Sodium 100 0 84 110 129 110 65 28
tyropanoate
20/2Hr. × 5
0 24 21 21 36 63 27
Iopanoic
100 0 6 24 66 142 208 127
acid 20/2Hr. × 5
0 21 35 65 106 166 216
Sodium 100 1 38 93 204 365 383 230
iopanoate
20/2Hr. × 5
0 28 39 73 193 345 296
______________________________________
The foregoing data again show that the maximum blood levels obtained with the divided dose regimen of sodium tyropanoate were much less, about one-half, than the maximum levels obtained with an equivalent single initial dose, whereas the quality of visualization was essentially the same. By contrast, iopanoic acid and its sodium salt were not only much slower in producing adequate visualization, but there was no significant difference in the maximum blood levels obtained whether administered in one initial dose or in divided doses.
Claims (3)
1. A process which comprises administering orally to a mammal possessing a gallbladder, a single undivided dose in a sustained or controlled release formulation or intermittently over a period of between about four and about ten hours, an amount of sodium tyropanoate of between about 25 and 100 milligrams per kilogram of body weight of the mammal, whereby a concentration of iodine in the gallbladder sufficient to provide adequate X-ray visualization of the gallbladder is obtained, while maintaining the maximum iodine concentration in the blood significantly lower than the maximum iodine concentration in the blood obtained by oral administration of an initial single dose of the same total amount of sodium tyropanoate.
2. The process according to claim 1 in which the sodium tyropanoate is administered in from three to six approximately equally divided doses at approximately equal intervals over a period of between 4 and 10 hours.
3. A process which comprises administering orally to a mammal possessing a gallbladder a sustained release formulation comprising an amount of sodium tyropanoate of between about 25 and 100 milligrams per kilogram of body weight of the mammal, whereby a concentration of iodine in the gallbladder sufficient to provide adequate X-ray visualization of the gallbladder is obtained while maintaining the maximum iodine concentration in the blood significantly lower than the maximum iodine concentration in the blood obtained by oral administration of the same amount of sodium tyropanoate alone.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/479,634 US4002731A (en) | 1974-06-17 | 1974-06-17 | Diagnostic process using sodium tyropanoate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/479,634 US4002731A (en) | 1974-06-17 | 1974-06-17 | Diagnostic process using sodium tyropanoate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US4002731A true US4002731A (en) | 1977-01-11 |
Family
ID=23904796
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US05/479,634 Expired - Lifetime US4002731A (en) | 1974-06-17 | 1974-06-17 | Diagnostic process using sodium tyropanoate |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US4002731A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5264422A (en) * | 1986-06-30 | 1993-11-23 | Fidia S.P.A. | Esters of alginic acid with steroidal alcohols |
| US5336668A (en) * | 1986-06-30 | 1994-08-09 | Fidia, S.P.A. | Esters of alginic acid |
| US5498422A (en) * | 1991-04-08 | 1996-03-12 | Nippon Shinyaku Company Limited | Sustained release capsule |
| EP1976489A1 (en) * | 2006-01-27 | 2008-10-08 | CJ CheilJedang Corporation | Multiple unit type sustained release oral formulation and process for the preparation thereof |
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|---|---|---|---|---|
| US1815902A (en) * | 1927-07-16 | 1931-07-28 | Nat Aniline & Chem Co Inc | Device for administering medicaments |
| US2436270A (en) * | 1944-05-22 | 1948-02-17 | Schering Corp | Polyiodo diaryl aliphatic acids and process for their manufacture |
| US2790748A (en) * | 1952-05-13 | 1957-04-30 | Schering Corp | Contrast agent |
| US2801203A (en) * | 1951-03-22 | 1957-07-30 | Byk Gulden Lomberg Chem Fab | X-ray method of digestive enzyme diagnosis using protected core of contrast agent |
| US2895988A (en) * | 1957-09-05 | 1959-07-21 | Sterling Drug Inc | Acylated trhodoaminophenylalkanoic acids and preparation thereof |
| US3042715A (en) * | 1958-12-03 | 1962-07-03 | Chemie Linz Ag | Iodine-containing benzoic acid amides and a process of making same |
| US3133863A (en) * | 1961-03-10 | 1964-05-19 | Strong Cobb Arner Inc | Sustained release therapeutic tablet compositions comprising organic solvent-gelled gums |
| US3144479A (en) * | 1958-08-07 | 1964-08-11 | Chemie Linz Ag | New iodine-containing benzoic acid esters |
| US3184386A (en) * | 1958-05-02 | 1965-05-18 | Burroughs Wellcome Co | Prolonged action medicinal tablets |
| US3226431A (en) * | 1960-06-21 | 1965-12-28 | Bracco Ind Chimica Spa | X-ray contrast agent |
-
1974
- 1974-06-17 US US05/479,634 patent/US4002731A/en not_active Expired - Lifetime
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1815902A (en) * | 1927-07-16 | 1931-07-28 | Nat Aniline & Chem Co Inc | Device for administering medicaments |
| US2436270A (en) * | 1944-05-22 | 1948-02-17 | Schering Corp | Polyiodo diaryl aliphatic acids and process for their manufacture |
| US2801203A (en) * | 1951-03-22 | 1957-07-30 | Byk Gulden Lomberg Chem Fab | X-ray method of digestive enzyme diagnosis using protected core of contrast agent |
| US2790748A (en) * | 1952-05-13 | 1957-04-30 | Schering Corp | Contrast agent |
| US2895988A (en) * | 1957-09-05 | 1959-07-21 | Sterling Drug Inc | Acylated trhodoaminophenylalkanoic acids and preparation thereof |
| US3184386A (en) * | 1958-05-02 | 1965-05-18 | Burroughs Wellcome Co | Prolonged action medicinal tablets |
| US3144479A (en) * | 1958-08-07 | 1964-08-11 | Chemie Linz Ag | New iodine-containing benzoic acid esters |
| US3042715A (en) * | 1958-12-03 | 1962-07-03 | Chemie Linz Ag | Iodine-containing benzoic acid amides and a process of making same |
| US3226431A (en) * | 1960-06-21 | 1965-12-28 | Bracco Ind Chimica Spa | X-ray contrast agent |
| US3133863A (en) * | 1961-03-10 | 1964-05-19 | Strong Cobb Arner Inc | Sustained release therapeutic tablet compositions comprising organic solvent-gelled gums |
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| Title |
|---|
| Fischer et al., Investigative Radiology, vol. 9, pp. 24-31 (No. 1, Jan. - Feb. 1974). * |
| Koehler et al., Radiology, vol. 108, pp. 517-519, Sept. 1973. * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5264422A (en) * | 1986-06-30 | 1993-11-23 | Fidia S.P.A. | Esters of alginic acid with steroidal alcohols |
| US5336668A (en) * | 1986-06-30 | 1994-08-09 | Fidia, S.P.A. | Esters of alginic acid |
| US5416205A (en) * | 1986-06-30 | 1995-05-16 | Fidia, S.P.A. | New esters of alginic acid |
| US5498422A (en) * | 1991-04-08 | 1996-03-12 | Nippon Shinyaku Company Limited | Sustained release capsule |
| EP1976489A1 (en) * | 2006-01-27 | 2008-10-08 | CJ CheilJedang Corporation | Multiple unit type sustained release oral formulation and process for the preparation thereof |
| EP1976489A4 (en) * | 2006-01-27 | 2011-04-13 | Cj Cheiljedang Corp | Multiple unit type sustained release oral formulation and process for the preparation thereof |
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